3,5,6-substituted-6-(trifluoromethyl)-hydrouracils

ABSTRACT

Herbicidal 3,5,6-substituted-6-(trifluoromethyl)-hydrouracils are provided having the formula:   WHEREIN: X is halogen or lower alkyl; Y is halogen; R1 is halogen, hydroxy, alkoxy or haloalkoxy; and R2 is hydrogen, alkyl, substituted alkyl, phenyl, cyclohexyl, cyclopentyl, substituted phenyl, or alkenyl.

United States Patent Lutz et al.

[ June 13, 1972 54] 3,5,6-SUBSTITUTED-6- (TRIFLUOROMETHYL)- HYDROURACILS [72] Inventors: Albert William Lutz, Montgomery Township; Richard William Feeny, Hightstown, both of NJ.

[73] Assignee: American Cyanamid Company, Stamford,

Conn.

[22] Filed: March 17, 1970 [21] Appl. No.: 20,382

Related US. Application Data [63] Continuation-impart of Ser. No. 804,708, March 5,

1969, abandoned.

Primary ExaminerNicholas S. Rizzo Assistant ExaminerAnne Marie T. Tighe AttorneyLawrence W. Flynn [57] ABSTRACT Herbicidal 3,5,6-substituted-6-(trifluoromethyl)-hydrouracils are provided having the formula:

X N-Rz wherein:

X is halogen or lower alkyl; Y is halogen;

R is halogen, hydroxy, alkoxy or haloalkoxy; and R is hydrogen, alkyl, substituted alkyl, phenyl, cyclohexyl,

cyclopentyl, substituted phenyl, or alkenyl.

11 Claims, No Drawings 3 ,5 ,6-SUBSTITUTED-6-(TRIFLUOROMETHYL)- HYDROURACILS CROSS REFERENCE TO RELATED APPLICATION This is a continuation-in-part application of application, 5 Ser. No. 804,708, filed Mar. 5, 1969, now abandoned.

BACKGROUND OF THE INVENTION U. 5. Pat. No. 3,322,526 relates to substituted hydrouracils of the formula:

3 5 43 N-R1 B2 6 wherein groups R R are broadly defined. This patent also suggests that such compounds exhibit herbicidal activity and proposes four methods for the preparation of compounds of the above formula. However, it should be noted that the patentee does not contemplate the 6-halo, 6-hydroxy, 6-alkoxy, or 6-haloalkoxy-6-(trifluoromethyl)hydrouracils of the present invention or a method for their manufacture.

He does suggest four methods for the preparation of his dihydrouracils. These include catalytic hydrogenation of a uracil of the formula:

to yield the dihydrouracil W wherein R is stated t o behydrogen, alkyl or alkoxy. Since this reaction adds hydrogens across the double bond, it does not lend itself to preparation of compounds of the present inventron.

The second method of the patentee suggests cyclization of a substituted B-amino propionate with an isocyanate.

The reaction is illustrated as follows:

R 3," H\ R2 R4 0 N-CC-COOCH3 R1NCO i i R: N R1 50 R6 4 2 If this reaction was to be employed for the preparation of tlie compounds of the present invention, R in the B-amino propionate would have to represent trifluoromethyl and R, would have to be halo, hydroxy, alkoxy or haloalkoxy. To the best of applicants knowledge these compounds have not been disclosed in the literature and no method for their preparation has been suggested.

The third method proposed by the patentee involves the reaction of a substituted urea with an a, ,B-unsaturated acid as illustrated below:

Again, the prior art appears to be devoid of afiunsaturated acids of the above formula in which R,, is trifluoromethyl, R is halo, hydroxy, alkoxy or haloalkoxy and R is halogen or alkyl. It also appears to be devoid of methods for making such compounds.

The fourth and final method described by the patentee for preparing his dihydrouracils involves exchange of certain functional groups without disturbing the dihydrouracil nucleus. The reaction is illustrated as follows:

R5 N HOV 0 11+ NR1 Cl 01 R2 R2 6 A This final method, like those previously described, also fails to describe or anticipate the present invention, for heretofore the intermediate compounds necessary to prepare the patentees starting materials, i.e. 6-(trifluoromethyl)-uracils of the formula:

H Ra N BAV =0 wherein R is hydrogen, lower alkyl or halogen and R is alkyl, alkenyl, phenyl, substituted phenyl, substituted alkyl, cyclohexyl or cyclopentyl, have not been available or disclosed in the art. A complete description of these compounds and their preparation is provided in copending applications Ser. Nos. 737,288, filed June 17, 1968, now US. Pat. No. 3,580,913 and 737,308, filed June 17,1968.

SUMMARY OF THE INVENTION This invention relates to novel 3,5,6-substituted-6- (trifluoromethyl)hydrouracils and a method for using said compounds. More particularly, this invention relates to hydrouracils which are effective herbicides and have the formula:

C Fa g 5 3 N--R X7 4 2 Y i wherein:

X is selected from the group consisting of halogen and lower alkyl;

Y is halogen;

R is selected from the group consisting of hydroxy, alkoxy,

halogen, and haloalkoxy; and

R is selected from the group consisting of hydrogen, alkyl,

alkenyl, substituted alkyl, phenyl, cyclohexyl, cyclopentyl, and substituted phenyl.

The compounds of this invention may also exhibit tautomeric forms as shown by way of example below:

5-bromo-5-methyl-6-methoxy-6-(trifluoromethyl)-hydrouracil Process The 3 ,5 ,6-substituted-6-( trifiuoromethyl )hydrouracils of this invention are prepared by reacting a 3-substituted or a 3,5-substituted-6-trifluoromethyl uracil of the formula:

wherein, W is hydrogen, halogen or lower alkyl and R, is as described above, with A. a halogen in the presence of water,

B, a halogen in the presence of an alcohol having from 1 to 6 carbon atoms such as methanol, ethanol, n-propanol, isopropanol, butanol, Z-butanol, pentanol, or the like,

C. a halogen in the presence of a halogenated alcohol such as 2-chloroethanol, l-chloro-2-propanol, 1,3-dichloro-2- propanol, 3-bromo-l-butanol, 4-chloro-1-butanol, 2- bromoethanol or the like, or

D. a halogen in the presence of water followed by treatment of the thus formed reaction product with a thionylhalide such as thionylchloride, thionylbromide, or thionylfluoride.

Reactions (A), (B), and (C) are graphically illustrated below:

H N F; 0

w W halogen Ra(Z)uOH W N-Rz (Y F 0 F 0 N R3(z)..0 =0 3( )n OH X N-m X NRz Y 1 Y I a a e O i a wherein:

W is hydrogen, halogen or lower alkyl; X is halogen or lower alkyl; Y is halogen; z is halogen; n is an integer of from 0 to 2;

R is hydrogen or alkyl of 1 to 6 carbon atoms; and R is hydrogen, alkyl, substituted alkyl, phenyl, cyclohexyl,

cyclopentyl, alkenyl, or substituted phenyl. Reaction (D) employs the reaction product of (A) and involves contacting said product with a thionylhalide to yield the LII We have found that these reactions (A through D) are generally exothermic and that the temperature at which each of said reactions is carried out is critical. While temperatures between about 25 and C. generally give optimum efiiciency, such reactions may be carried out over a wider temperature range as, for example, between about 15 C. and C. In any event, the reaction temperature must be maintained sufficiently high to pennit hypohalous acid or organic hypohalites to add across the double bond of the uracil but below that temperature at which hypohalite is liberated from the hydrouracil formed. In practice said reactions will generally be conducted at atmospheric pressure, however, subatmospheric and superatmospheric pressures may be used if desired. It has also been determined that an inert solvent such as benzene, chloroform or carbon disulfide may be used in reactions (A-D) without adversely effecting product yield. This prac tice, however, is generally most advantageously employed where the reaction mixture tends to be viscous, i.e. in reactions utilizing the higher alcohols or the halogenated higher alcohols.

As will become apparent from the examples set forth below, reaction (A) yields formula (I) hydrouracils wherein R is hydroxy; (B) yields similar compounds in which R, is alkoxy; (C) yields like compounds where R is haloalkoxy and (D) provides the formula (I) compounds in which R is fluorine,

chlorine or bromine. Moreover, from the appended examples it will also become apparent that in reactions (A), (B) and (C) when W in the formula (11) compound represents hydrogen, X and Y in the formula (III) hydrouracil are the same and represent the halogen employed in the reaction. However, when W represents a halogen which differs from the halogen (Y) added to the reaction mixture, a hydrouracil with mixed halogens at the 5 position is formed, X representing the halogen W and Y the halogen added. Similarly, where W is lower alkyl, such as methyl, ethyl, propyl, isopropyl, butyl or sec butyl, the hydrouracil with a lower alkyl and a halogen at the 5 position is formed.

Reactants As described in copending applications Ser. Nos. 737,308,filed June 17,1968 and 737,288,fi1ed June 17, 1968, now U.S. Pat. No. 3,580,913., the 3,5-substituted-6- (trifluoromethyl)uracils (ll) employed as starting materials in the manufacture of the compounds of the present invention wherein R is not hydrogen are prepared by an ester of a B- amino-a,B-unsaturated acid with an isocyanate in the presence of an inert solvent and an alkali metal hydride or alkali metal lower alkoxide. Graphically this reaction may be illustrated as follows:

wherein R is halogen, lower alkyl or hydrogen, R is lower alkyl and R, is alkyl, substituted alkyl, phenyl, cyclohexyl, cyclopentyl, substituted phenyl or alkenyl. In the case where the R substituent of the compounds of this invention is hydrogen, the required starting materials (11) are either available to those skilled in the art or else can be prepared from available materials in accordance with procedures known to those skilled in the art such as, for example, that reported by Kaiser and Burger in J. Org. Chem. 24, 113 (1959).

Solvents particularly adapted to use in these reactions are the one to eight carbon alcohols such as methanol, ethanol, propanol, octanol, t-butanol, and the like; the glycol ethers such as diethylene glycol dimethylether, ethylene glycol dimethylether, ethylene glycol diethyl ether and the like; and dipolar aprotic solvents such as dimethylsulfoxide, dimethylformamide, methyl isobutyl ketone, N,N-dimethylacetamide, and the like.

Among the bases which are suitable for use in these reactions are potassium-t-butoxide, sodium methoxide, sodium methoxide, sodium hydride, potassium hydroxide, pentamethylguanidine, potassium hydride and sodium metal. The reactions may be carried out over a wide temperature range of from about 15 C. to 100 C., with a preferred range of about 25 C. to 50 C. It has also been found that about moles to 1.5 moles of base per mole of reactant provide optimum product yields.

Utility The inventive compounds are potent preand post-emergence herbicides as amply shown by the illustrative data of Examples 1 through 4 hereinbelow.

The herbicidal compositions of the present invention may be prepared as solutions of water soluble salts, as emulsifiable concentrates, dusts, dust concentrates and wettable powders which lend themselves to application with conventional spraying and dusting equipment.

Representative formulations which may be prepared are provided below (percentages are by weight):

Aqueous Solution 22.5% 5,5-dichloro-3-isopropyl-6-methoxy-6- (trifluoromethyl)hydrouracil 8.0% triethylamine q.s.100% water (a lower alcohol such as methanol,

ethanol or the like may also be used as cosolvent).

Emulsifiable Concentrate 25%- 5,5-dichloro-3-isopropyl-6-methoxy-6- (trifluoromethyl)hydrouracil 10% nonionic-anionic emulsifier (mol 77L [by Wm. Cooper and N ephers1) 65% methylisobutylketone (Dispersed in water for application) Wettable Powder In practice the compositions of the invention may be used to control a wide variety of monocotyledonous and dicotyledonous plants. They may be used for both post-emergence and pre-emergence control of plants by application to plant foliage or to soil containing seeds or other propagules of plants and find particular utility as selective post-emergence and pre-emergence herbicides. As selective post-emergence herbicides they are especially useful for controlling broadleaf weeds and grasses in the presence of crops such as corn, cotton and sorghum. As selective pre-emergence herbicides they are especially useful for controlling weeds and grasses in the presence of crops such as corn, sorghum, soybeans, liniuhenns, cotton, peas. stringbeans, watermelons, cucumbers, squash mid pumpkin.

The following cxinnples are provided to further illustrate the invention.

EXAMPLE 1 POST-EMERGENCE HERBICIDAL ACTIVITY The post-emergence herbicidal activity of the compounds of the present invention is demonstrated by the following tests wherein a variety of monocotyledonous and dicotyledonous plants are treated with test compounds dispersed in aqueousacetone mixtures. In the tests seedling plants are grown in jiffy flats for about 2 weeks. The test compounds are dispersed in 50/50 acetone/water mixtures in sufficient quantity to provide the equivalent of about 0. 125 to 10 pounds per acre of active compound when applied to the plants through a spray noule operating at 30 p.s.i. for a predetermined time. After spraying, the plants are placed on greenhouse benches and are cared for in the usual manner, commensurate with conventional greenhouse practices. Two weeks after treatment, the seedling plants are examined and rated according to the Herbitoxicity Index provided below. The data obtained are reported in Table l.

HERBITOXICITY INDEX 9 100 percent reduction in stand 9-= l or 2 stunted plants remaining 8 -100 percent reduction in stand 7 70-85 percent reduction in stand 6= 60-70 percent reduction in stand 5 50-60 percent reduction in stand 4= 40-50 percent reduction in stand 3 30-40 percent reduction in stand 2 20-30 percent reduction in stand 1 10-20 percent reduction in stand 0 no apparent effect s severe injury m moderate injury l= trace to slight injury no test c chlorosis g= growth retarded a abnormal growth r= regrowth PLANT ABBREVIATIONS AW Alligator weed BW Bindweed CT= Canada thistle JG Johnsongrass NS Nu tsedge QG Quackgrass KO Kochia LA Lambsq uarters Mu Mustard PI Pigweed BA Barn yardgrass CR Crabgrass GRF= Greenfoxtail W0 Wild Oats M1 Millet PF Parrots Feathers COR= Corn COT= Cotton SOY= Soybean SB Sugarbeets T0 Tomato WH Wheat RA Radish LB Lima beans SE Sorghum :EoQmo z 6 OHF kCIQU Q Q Q Q Q Q Q Q Q Q Q Q Q E Q Q Q Q Q Q 2 Q Q Q Q Q Q Q Q Q Q Q 5 0 0 w 6 Eomomo z 6 0 0:6 Q Q Q E Q Q Q Q Q Q Q Q Q Q Q Q Q Q 2 Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q E Di 0 \6 x movmo z 6 Hunuunnnfi Q Q Q Q Q Q Q Q Q Q Q QQ o f 0E6 ....Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q 2 Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q m om o Q0 x movmo z 6 HHHHHHHHH Q Q E Q Q Q Q Q Q Q Q QQ o r 050 Q Q E Q Q Q Q Q Q Q Q Q Q Q Q Q Q 2 Q Q Q E Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q m 05 o 6 :EoEo z l6 o h Q6 Z Q Q Q Q Q Q Q Q Q Q Q Q 5 Q Q oi QMQ F FQQ PQ :7 9 Foo moo Q: 03 E6 Q6 3 E a: 4 0% 60 m2 2 so Q; Q: Q Q 2 5 .83 QQQE= 8 665.3% $5.: .295.

6 EU Z 6 o 050 2 I? o o o I: c a n 1 I I F a IQ m a W H /o o \6 r 6 z a 5 a n o c a c a Q m i h m a a Q n ........m 6 a p a w o z Q 8 a .51.; m a g a Q m m m o o E 3650 2 6 o r z a w m a a mm Q a a m S m c n w a x movmo z 6 n o a a a a a u m w x a a a a a Q a a m a Q a N. Q Q Q m a 2 o 050 a a a p a a a a a Q Q Q a Q a H z m m m ::::w m w a Q a Q a a a N. m a Q v m oi o 5 fimovmo z m Q F om s o a a Q o c I1.I..........l....l.......Q o o m a Q Z\/ a m Q m a .111. N. a u a a a o o a a a S w m 0 ,a F; 09 mm Mom r o moo mm 03 E8 M0 4m 5 b2 .5 0M so m2 on so 3m 34 w 2 0 31 8 330 was? 3334 33 1:52am EOE umfi HHHHHHHHHHHH E m m u u N a a E 1 1 n m a m n h m u a a m o m WAHVSO C O -Z rd 7 o 2:5 w Q 5 HH 9 a a a a m a X z m m a Q Q m n m m m a Q H :59 U a la b :6 a a Q a Q a In HH HWW HHHH a a a n m m m m a m a I I 1 I I l I I I I l I I I v 1 0 5 nmmcol O Q F 025 z a Im a m m E n n a a a a w n o O 5 25050 2 5 m a n a m m a 1 w a P 5 a a -O 4. c m a I. 5 m J m we 09 5 wow rwoo moo ,2 9: -56 mo m E :2 45 0M 00 m2 2 Bo 5 3 Y w" E 5 0 269$ 12:54 23?: 3:53am cum: 928

EXAMPLE 2 SELECTIVE PRE-EMERGENCE HERBIClDAL ACTIVITY The selective pre-emergence herbicidal activity of the corn- 5 pounds of the invention is exemplified by the following tests in which the seeds of a variety of monocotyledonous and dicotyledonous plants are separately mixed with potting soil and planted on top of approximately one inch of potting soil in separate pint cups. After planting, the cups are sprayed with l0 the selected aqueous-acetone solution containing test compound in sufficient quantity to provide the equivalent of about 0.25 to 25 pounds per acre of test compound per cup. The treated cups are then placed on greenhouse benches and TABLE II Treat- Eiegr; Annual weeds Crops aer) KO LA MU PI BA CR CRF W0 HI COR COT SOY SB WI PA LB SG F80 I 3 16 0 9m 9 9' o s 1 0 0 u a CH Ij=o C1 CH(CH3)2 H 4 l) 9 0 9 9 9- t 9- N 1 s 9 9 n n nn o C11 0 =0 M 0 9 ll 9 8 6 0 0 34 3g 9- 9 8g 3g 3g t C1 N-CH(CHa)z Cl I 0 II 4 9- 9 9 9 0 I 9 9 t 1. F 0 N g 1 3 9- 9 9 5 8g 9- 0 0 CzUaO =0 4 9 9- o 9- ii a; 3g t 0 0 NCH(CII;)

Fig 4 9 9- 9 9 0 n- 9 9 t tg 9 3g N 9 9 r A C aO 0 $4 9 8g tg 3g t t 0 0 0 Cl 7 N-CHCH2CH; C 1| 0 H 4 9 9 9 9 9- 9 9 t t 0 7 F80 N g g mCaHO 3 3 E 9 9 9 g g t 0 0 0 C1 CH(CH:)2

Cl I

F 0 g 26 9 6g 5c ts HO =0 Br NCH(CH H 9 9 9 9 9 9 9 t 5 F30 g N 0 0 CHaC 54 7g 7g 9 l] t 3 3g 8 C1 N-omcnm Br A 0 g 25 9 9 tg 0 HO 0 C1 7 N-CH(CH3)2 Br I 4 9 9 sg tg 0 tg t, s 9 F30 $6 9- 9- 9- 9 I33 0 0 o o t 9 H N 01150 To C 1 V V r v V a V TABLE II -(on\inued Treatpap}: Annual weeds Crops acre) KO LA MU PI BA CR CRF W HI COR COT SOY SB WI PA LB SG H FC 4 9 9 9 g 9 mg t aga 0 age 0 011:0 8 9 3 09- mg 0 0 0 m 0 C1 NCH3 F 0 g 9 3a mg 0 01 l-o Cl NCH(CH3)2 C] H O EXAMPLE3 SELECTIVE PRE-EMERGENCE HERBICIDAL AC1 IVITY Selective pre-emergence herbicidal activity of the compounds of the present invention is demonstrated in the following tests wherein test compounds are dissolved in /50 acetone/water solutions and applied in dilute aqueous solution to seeded plots with a standard spraying apparatus operated so as to deliver 57 gal./acre of test solution which provides the equivalent of 0.50, 1.0, 1.5, 2.0 or 3.0 lbs. of active ingredient/acre of seeded plot. The soil is prepared in the normal manner by plowing and harrowing. Seeds of the broadleaf jimpson weed) and grasses (i.e., foxtail and crabgrass) are broadcast over the plot and disked into the soil to assure heavy weed infestation. The plots, 5 ft. wide and 20 ft. long, are then planted with corn, soybeans, limabeans, wheat and sorghum in rows approximately 10 inches apart. When plantings are complete, the plots are sprayed with aqueous solution of the test compounds using the sprayer to deliver the solutions essentially uniformly over the test plots. Untreated plots which have been similarly planted are employed as controls. At intervals of about 24 and 47 days after planting, the plots are examined and rated as to herbicidal activity according to the index set forth below. At both readings control plots adjacent to test plots are heavily infested with all species of the broadleaf weeds and grasses employed in the tests. Data obweeds (i.e., pigweed, lambsquarters, smartweed, ragweed and, 35 tained a re reported in Table III below.

TABLE III 7 q First rating 24 days Soy- Sor- Rate, Wheat Corn beans Corn ghum Compound 1b./acre 1 2 3 4 5 A GW ABW C F H 2 0 0 0 0 7 8 N 1 2 0 2 0 0 9 9 01530 O 2 4 0 0 0 2 8 10 3 8 0 0 1 3 9 10 C1 NiC H7 0 a .i a Am, A

0 Fa H 95 3 0 0 0 4 7 8 1 4 1 2 0 3 7 10 C2H5C O 2 6 0 2 O 1 8 10 3 8 0 3 0 3 10 10 C1 N-iCaH1 C F; H )6 4 0 3 0 1 6 8 l 4 0 2 0 2 9 10 n-CaH7O O 2 3 0 3 0 2 8 10 01 N i-C:H1

C F; H 3 0 2 0 0 6 8 1 5 0 4 0 2 9 9 CHsO O 1% 5 0 2 0 3 9 10 C N-secC H,

TABLE III tuntinued Second rating 47 days Soy- Sor- Rate, Wheat Corn beans Corn ghum Compound lb./acra 1 2 3 4 5 AGW ABW F3 H )6 X X X X X 7 8 N 1 X X X X X 7 8 CHaO =0 2 I X X X X 8 9 3 I X X X X 9 10 c1 NiC2H (r M H X X X X X 7 9 N l X X X X X 9 (mm; 0 2 K X X X X 0 10 3 l X X X X 0 10 I Nl(3.1ll

C I: ll X X X X X 8 l X X X X X 9 l0 n-CalizO O 2 K X I X X 10 Cl N-iCaH1 C Fa H 5 K X X X X 5 U N 1 K X X X X 5 10 CHaO 0 1 K X X X X 8 10 NS80C4H9 Herbitoxicity Index Field Rating EXAMPLE 4 35 (l)= Ifigqeffect SELECTIVE POST-EMERGENCE HERBICIDAL a 2 alteration by visual ACTIVITY observation based on 3: reductionin Standreducdon Selective post emergence herbicidal activity 1s demon in fresh weight f f li g 40 strated In the following tests wherein 5 by 20 foot plots are 4 40% malformation and plant prepared as described in Example 3 above. As indicated, they 5 5007 "3: 7 f example are sown with seeds of broadleaf weeds and grasses and then 23x32 or less is planted with soybeans, corn, wheat and sorghum in rows ap- 6 0 acceptable f crop proximately 10 inches apart. When the com has grown to ap- 7 selectivity. 45 proximately 16 inches, the soybeans to 3 inches, the 8 sor hum to 8 inches, the wheat to 5 inches and the weeds to 2 9 8 10 Complete Kill x Crop not injured I= Significant injury K Crop Killed k to 3 inches in height, the planted plots are treated, at constant rates of application, with aqueous-acetone solutions of the test compounds containing 0.5 percent by vol. of a wetting AGW: Annual grass weeds 50 agent, containing as the principal active ingredient dodecyl ABW Annual broadleaf weeds ether of polyethylene glycol. Eighteen days after application Ft i l iiiexefle i eei i lstb siiel efi sa xlh TABLE IV Soy- Sor- Rate, Corn Wheat beans Corn ghurn Compound lb./acre 1 2 3 4 5 A GW ABW C F: H V 0 3 10 1 1 6 10 N $6 0 5 10 1 1 4 10 CH: CW -0 l. 1 10 10 1 4 8 10 C i N-i-C3H7 C F: H K 0 2 6 0 l 10 N 0 4 10 1 2 6 1O CgHaO =0 1 9 l0 1 1 10 C1 N-i-CgHy G1 I I C F; H M 0 2 3 0 0 4 8 N 1 3 8 1 l 5 9 H10 :0 1 1 3 1 2 5 10 (fl NSOCC4lig rating index used is provided in Example 3 above and the data obtained are provided in Table IV below where it can be seen that effective control of broadleaf weeds and partial control of grasses is obtained at the one-fourth, one-half and 1.0 lb./acre rates. Little or no injury to corn is noted at any of these rates and only very slight detectable injury is noted on sorghum at such rates. Untreated control plots are heavily infested with all species of the broadleaf weeds and grasses used in these tests and identified in Example 3 above.

EXAMPLE PREPARATION OF 5,5-DIBROMO-6-HYDROXY-3- ISOPROPYL-6-(TRlFLUOROMETI-IYL)HYDROURACIL 0.50 gms. of 5-bromo-3-isopropyl-6-(trifluoromethyl; uracil is dissolved in 50 ml. of water and treated with bromine while stirring said mixture for 3 hours. A white solid forms in said mixture, is separated from said mixture and recrystallized from chloroform'and petroleum ether to give the product which has a melting point of 167-168.5 C. and analyses as follows:

Calculated:

C, 24.14; H, 2.28; N, 7.04; Br, 40.16; F, 14.32. Found:

C, 24.17; H, 2.33; N, 7.13; Br, 39.95; F, 14.62.

EXAMPLE 6 PREPARATION OF 5,5-DICI-ILORO-6-HYDROXY-3- ISOPROPYL-6-(TRIFLUOROMETI-IYL)I-IYDROURACIL 0 F g C F3- 0 HO O NCH(CH3)2 012 w 01 NCH(CH:I)2

3-Isopropyl-6-(trifluoromethyburacil (4.0g, 0.018 moles) is suspended in 50 ml. H )O. C1 is bubbled into this suspension for 5 hours while maintaining the temperature below about 50 C. After this time, TLC (2 X 8 Silica Gel plate, 1:5 HOAc- (bl-l) shows one spot for the suspended solid, and it does not correspond to starting material. The solid is removed, and recrystallized from CI-lCl to give white solid, mp. l63165 C.

EXAMPLE 7 PREPARATION OF S-CHLORO-S-METHYL-G- HYDROXY-3-ISOPROPYL-6- (TRIFLUOROMETHYL)HYPROLIRACILV V The above compound is prepared following substantially the procedure of Example 6 except that 3-isopropyl-6- (trifluoromethyDuracil is replaced with 3-isopropyl-5-methyl- 6-(trifluoromethyl)uraci1.

is dissolved in 50 ml. absolute methanol. Chlorine is added to this solution and an exotherm occurs, however, the temperature of the reaction is maintained below about 60 C. Chlorine addition is terminated when the exothenn ceases and the methanol is then stripped. The resulting solid recrystallizes from 1:1 95% EtOH-H O to give white product (4.85 g., 83.6 percent yield), m.p. l29-131 C. C H CI F N 0 calculated: C, 31.09; H, 2.93; CI, 22.94; F, 18.44; N, 9.06. B un 0-7511. .42 2 2: 9;

EXAMPLE 9 PREPARATION OF 5,5-DICI-ILORO-3-lSOPROPYL-6-( 1,3-

DlCHLOR0-2-PROPOXY)-6- (TRIFLUOROMETHYL)HYDROURACIL C1-C3: H

2 OF; N O H O C1 0 NCH(CH3)g The above compound is prepared following the procedure of Example 8 except replacing methanol with 1,3-dichloro-2- propanol.

EXAMPLE 10 PREPARATION OF 5,5-DIC1-lLORO-3-( 1,2- DICHLOROISOPROPYL)-6-METHOXY-6- (TRIFLUQROMETHYL)HYDROURACIL The above compound is prepared following the procedure of Example 8 except that 3-isopropy1-6-(trifluoromethyl) uracil is replaced by 3-(1,3-dichlorOisoprOpyl)-6- EXAMPLE LL PREPARATION OF 5,5-DIC1-1LORO-3-( 1,2- DIHYDROXYISOPROPYL)-6-METHOXY-6- TRIPLUO OMETII U ACIL The above compound is prepared following the procedure Using the procedure of Example 8, Q0225 moles of 3+ of E m 8 z g fl g ig'g 9 i 2 1O propyl-6-(trifluoromethyl)uracil is dissolved in 150 ml. of abracl ls rep ace y l y roxylsopropy solute ethanol and the mixture treated with chlorine gas. An

(mfluommethynuracll' exotherrn results with the temperature of the reaction mixture EXAMPLE 12 increasing to 60 C., however, it is not permitted to exceed said temperature. The mixture is stirred, cooled and then PREPARATION OF 5,5-DlCHLORO-3-ALLYL-6- 15 poured into water yielding a white precipitate which is METHOXY-6-(TRIFLUOROMETHYL)HYDROURAC1L separated by filtration from the reaction mixture and has a melting point of l33-135 C. This product, 5,5-dich1oro-6- OF! H ethoxy-3-isopropv1-6-(trifluoromethyl)hydrouracil, is found 01130 N to have the following analysis:

I C 11 Cl 1- N 0 FV- Calculated: C, 35.63; H, 3.89; Cl, 21.03; F, 16.91; N, 8.31; O,

14.24. G Found: C, 35.46; H, 3.75; Cl, 21.16; F, 16.94; N, 8.31.

25 EXAMPLE 16 The above compound 1s prepared following the procedure of Example 8 except that 3-isopropyl-6-(trifluoromethyl)U- PREPARATION OF 3-SEC-BUTYL-5,5-DICHLORO-6- racil is replaced by 3-al1y1-6-(trifluoromethy1)-uraci1. METHOXY 6-( TRIFLUOROMETHYL )HYDROURACIL EXAMPLE 13 on g PREPARATION OF 5,5-D1CHLORO-3-n-HEXYL-6- CHzo To METHOXY-G-(TRIFLUOROMETHYL)HYDROURACIL O1 NC1Hn56c C 1 CFQ g H 01130 --O A solution of 0.085 moles of 3-sec-butyl-6- C] N'-CfiH13-n (trifluoromethyl)uracil in absolute methanol is treated with 01 chlorine gas and stirred for 3 hours with the temperature of W 7 7 40 the reaction mixture maintained below 35 C. The mixture is then poured into 300 ml. of water and stirred. A white solid Following the procedure of Example 8, a solution of 0.0038 forms and is Separated from the mixtura This product moles of 3-n-hexyl-6-(trifluoromethyl)uracil in 5 ml. of bmy| 5,5 dichloro 6 methoxy 6 (trifluommemyl)hydbw methyl alcohol is treated with chlorine gas. A slight exotherm rad], has a memng point f 33 35 insues but the reaction mixture is maintained below 30 C. The mixture is then poured into ice and a white precipitate EXAMPLE 17 f h 1t f 7 orms aving a me mg point 0 74 7 C This product, 5,5 PREPARATKON OF 55 DICHLORO 6 METHOXY 3 dichloro-3-n-hexyl-6-methoxy-6'( trifluoromethyl )-hydrouracil has the following analysis: PHENYL-6-( TRIFLUOROMETHYL)URAC1L C12 n z a N2 :1 5 H Calculated: c, 39.47%; H, 4.69; F, 15.61; c1, 19.42; N, 7.67; N

Found: c, 39.55; H, 4.42; F, 15.83; C], 19.41; N, 7.76. CI Q EXAMPLE 14 c1 PREPARATION OF 5,5-DlCHLORO-3-CYCLOHEXYL-6- The above compound is prepared the chlorination Of 3- phenyl-6-(trifluoromethyl) following the procedure described in Example 16; m.p. 23924lC.

CHSO EXAMPLE 1s 01 O PREPARATION or 5,5D1Cl-1LORO-6-METHOXY-3- C METl-l YL-6-( TRIFLUOROMETHYL)HYDROURACIL 0F H The above compound is prepared following the procedure OHSO N of Example 13 except that 3-r1-hexyl-6-(trifluoromethyl)- uracil is replaced by 3-cyclohexyl-6-(trifluoromethyl )uracil. Cl NOH3 C I EXAMPLE 15 e A e e e e The above compound was prepared by the chlorination of PREPARATION OF 5,5-D1CHLORO-6-ETHOXY-3- 3-methyl-6-(trifluoromethyl)uracil in methanol following the 1SOPROPYL-6-(TRIFLUORQMETHYL )HYDRQUEACIL procedure described in Example 1 mp. l33135 C.

EXAMPLE l9 PREPARATION OF 5,5-DIBROMO-6-METI-IOXY-3- PHENYL-(TRIFLUOROMETl-IYL)I-IYDROURACIL EXAMPLE PREPARATION OF 5,5-DIBROMO-6-METI-IOXY-3- M ETHYL-6-( TRIF LUOROMETI-IYL)HYDROURACIL or: E 011 0 Br I The above compound is prepared following the procedure of Example 18 except that 3-methyl-o-(trifluoromethyl)uracil is brominated instead of chlorinated.

EXAMPLES 21 TO 27 The compounds shown below are prepared in accordance with the procedures of Examples 17and 19 by merely selecting the appropriately substituted 6-(trifluormethyl)uracil reactant.

Exnm p10 Number Compound Compound or. H

CHaO

Example Number EXAMPLE28V 7' PREPARATION OF 5 ,S-DICI-ILORO-3-isopropyl-6- PROPOXY-6(TRIFLUOROMETI-IYL)HYDROURACIL OF; H

EXAMPLE 29 PREPARATION OF 5-BROMO-5-CHLORO-3- ISOPROPYL-6-METHOXY-6- IFLUQ SQEE H E)H D CIB N 5-CHLORO-6-HYDROXY-3-ISOPROPYL-6- (TRIFLUOROMETHYL)I-IYDROURACIL on H c F, H N N omo =0 H0 o and Br N-omoHol Br NCH(OH3)2 10.7 g. of Ethyl 3-amino-4,4,4-trifluorocrotonate in 20 ml. of dimethyl sulfoxide (DMSO) is admixed with 8.5 g. of potassium t-butoxide in 50 ml. of DMSO while maintaining the .reaction mixture at 25 C. 5.48 g. of Isopropylisocyanate is then added and the mixture stirred. The mixture is then poured into water and the resulting mixture extracted with ether. The aqueous phase is then acidified to pH 1 with HCl and extracted with ether. After water washing and drying the yellow solid, 3-isopropyl-6-(trifluoromethyl)uracil, is obtained. 7.4 g. of this product is then dissolved in 0.5N NaOH (0.04 mole) and 15 ml. of chloroform. Chlorine is then bubbled into the mixture. After stirring for 1% hours sodium bisulfite is added to discharge the color. The aqueous layer is then separated and extracted with chloroform. The chloroform extracts are washed with water and evaporated to dryness. The white solid,3-isopropyl-5-chloro-6- (trifluoromethyhuracil, is obtained. This product is then dissolved in methanol and treated with bromine while maintaining the reaction below about 31 C. After stirring the mixture is poured into water. A white solid forms which is collected by filtration and dried. This product, 5-bromo-5-chloro-3- isopropyl-6-methoxy-6-(trifluoromethyhhydrouracil, has a melting point of l29134 C. The filtrate from the above separation is then treated with chloroform and then pentane to give a white solid, m.p l75-l78 C. identified as 5-bromo- 5-chloro-6-hydroxy-3-isopropyl-6-(trifluoromethyllhydrouracil.

EXAMPLE 30 PREPARATION OF 5,S,6-TRlCHLORO-3-lSOPROPYL-6' (TRIFLUOROMETHYL)-HYDROURACIL CFa H completely dissolved in 25 ml. SOCl and stirred 36 hours at room temperature. After this time the reaction solution is slowly and carefully poured into H with external cooling. The resulting crude white solid is recrystallized from ethyl acetate to give product, 1.2 g. (30.5 percent yield) m.p. l'78-I80 C.

EXAMPLE 3! PREPARATION OF 5,5,6-TRIBROMO-3-ISOPROPYL-6- (TRIFLUOROMETHYL)-HYDROURACIL Following the procedure of Example 30, 5,5dibromo-3- isopropyl-6-hydroxy-6-(trifluoromethylJhydrouracil is dissolved in thionylbromide (SOBr and stirred at room temperature for 24 hours. The mixture is then poured into cold water which precipitates the product, 5,5,6-tribromo-3- isopropyl-6-(trifluoromethyl)hydrouracil.

EXAMPLE 32 PREPARATION OF 5,5-DICHLORO-6-METHOXY-6- (TRIFLUOROMETHYL)HYDROURACIL OF; H

N onto *0 Chlorine was bubbled into a solution of -trifluoromethyluracil (5.0 g., 028 mole, CL72 103) in 50 ml. absolute methanol with cooling to maintain a temperature of 30 C. or less. The addition of chlorine was stopped when the solid obtained by pouring an aliquot of the reaction solution into water showed no more unreacted starting material as shown by thin layer chromatography. The rest of the reaction solution was poured into water, stirred vigorously, and the resulting shiny white solid removed. After drying with reaction in the vacuum oven 6.43 g. (81.8 percent) product was obtained with m.p. 206208 C Analysis:

Calculated for C H C1 F N 0 C,25.64; H,l.79; Cl,25.23; F,20.28-, N,9.97.

Found: C,25.58; 11,1.72; Cl,25.40; 2032; N,9.82

EXAMPLE 33 PREPARATION OF 5 ,5-DlCHLORO-6-ETHOXY-6- TRIFLUOROMETHYL )HYDROURACIL The above compound was prepared following substantially the same procedure as in Example 32 except that the methanol was replaced with ethanol; melting point was l6917lC.

EXAMPLE 34 PREPARATION OF 5,5-DlCHLORO-6-PROPOXY-6- TRIFLUOROMETHYL )HYDROURACIL The above compound was prepared following substantially the same procedure as in Example 32 except that the methanol was replaced with n-propanol; melting point was 15 l-15 3 C.

EXAMPLE 35 PREPARATION OF 5,5-DICHLORO-6-HYDROXY-6- (TRIFEUOROMETHYL)HYDROURACIL CH3 H N OH -0 The above compound was prepared following substantially the same procedure as in Example 32 except that the methanol was replaced with water; melting point was l92-l9 4 C.

EXAMPLE 36 PREPARATION OF S-METHYL-5,6-DICHLORO-6- (TRIFLUOROMETHYL)HYDROURACIL 0215 C Fa H N Cl 0 NH CH S-Methyl-6-trifluoromethyluracil was prepared from ureas and ethyl 2-methyl-4,4,4-trifluoroacetoacetate in a manner similar to that reported by Kaiser and Burger in J. Org. Chem. 24, 113 (1959). This uracil is then converted to 5-chloro-5- methyl-Q-hydroxy-6-(trifluoromethyl) hydrouracil by a procedure substantially similar to that given by Example 6. The resulting 6-hydroxyhydrouracil is then transformed to the corresponding 6-chlorohydrouracil by the procedure of Example 30.

EXAMPLE 37 PREPARATION OF S-CHLORO S-METHYL-6- HYDROXY-6-(TRlFLUOROMETHYL)HYDROURACIL or; 1% OH 1. A 3,5,6substituted-6-(trifluoromethyl)hydrouracil ofthe lormuln:

wherein:

X is selected from the group consisting of halogen and lower alkyl of C -C Y is halogen;

R is selected from the group consisting of halogen, hydroxy, alkoxy of C -C and mono-and di-haloalkoxy of C -C and R is selected from the group consisting of hydrogen; alkyl of C -C alkenyl of C C mono-or di-substituted alkyl of C -C having a substituent selected from the group consisting of halogen, hydroxy and lower alkoxy of C,-C phenyl; cyclohexyl; cyclopentyl; and mono-0r di-substituted phenyl having a substituent selected from the group consisting of nitro, halogen, lower alkoxy of C -C mono-or di-haloalkoxy of C,C,, and trifluoromethyl,

and the tautomers thereof and the water soluble sodium,

potassium and ammonium salts of said compounds and tautomers, wherein said halogen and halo substituents are selected from the group consisting of fluorine, chlorine, bromine and iodine.

2. A compound according to claim 1, where R is alkoxy.

3. A compound according to claim 1 where R is hydroxy. 4. A compound according to claim 1 where 1 is a halogen selected from the group consisting of chlorine, fluorine and bromine.

5. A compound according to claim 1: 5,5- dichloro-3- isopropyl-6-methoxy-6-(trifluoromethyl) hydrouracil.

6. A compound according to claim 1: 5 ,5-dichloro-6-ethoxy-3-isopropyl-6-(trifluoromethyl) hydrouracil.

7. A compound according to claim 1: 3-sec-butyl-5, 5-

dichloro-6-methoxy-6-(trifluoromethyl )hydrouracil.

8. A compound according to claim 1: 5,5-dichloro-3- isopropyl-6-n-propoxy-6-(trifluoromethyl)hydrouracil.

9. A compound according to claim 1: 5,5-dichloro-6- methoxy--(trifluoromethyl )hydrouracil.

10. A compound according to claim 1: 5,5-dichloro-6- eth0xy-6-(trifluoromethyl)hydrouracil.

11. A compound according to claim 1: 5,5-dichloro-6-npropoxy-6-(trifluoromethyhhydrouracil. 

2. A compound according to claim 1, where R1 is alkoxy.
 3. A compound according to claim 1 where R1 is hydroxy.
 4. A compound according to claim 1 where R1 is a halogen selected from the group consisting of chlorine, fluorine and bromine.
 5. A compound according to claim 1: 5,5- dichloro-3-isopropyl-6-methoxy-6-(trifluoromethyl) hydrouracil.
 6. A compound according to claim 1: 5,5-dichloro-6-ethoxy-3-isopropyl-6-(trifluoromethyl) hydrouracil.
 7. A compound according to claim 1: 3-sec-butyl-5, 5-dichloro-6-methoxy-6-(trifluoromethyl)hydrouracil.
 8. A compound according to cLaim 1: 5,5-dichloro-3-isopropyl-6-n-propoxy-6-(trifluoromethyl)hydrouracil.
 9. A compound according to claim 1: 5,5-dichloro-6-methoxy-6-(trifluoromethyl)hydrouracil.
 10. A compound according to claim 1: 5,5-dichloro-6-ethoxy-6-(trifluoromethyl)hydrouracil.
 11. A compound according to claim 1: 5,5-dichloro-6-n-propoxy-6-(trifluoromethyl)hydrouracil. 